1. Field of the Invention
The present invention relates to a liquid crystal display apparatus and, more particularly, to a liquid crystal display apparatus used for both the reflective display scheme and the transmissive display scheme.
2. Description of the Related Art
In a dark environment such as indoors, generally, a liquid crystal display apparatus can obtain visible display by using transmissive display which performs display using transmitted light emitted by a surface light source arranged on the back surface of a liquid crystal panel. In a relatively bright environment such as outdoors, poor visibility is obtained by the transmissive display because of relative shortage in the brightness of the surface light source. When the surface light source emits light brighter than the ambient light, power consumption increases. On the other hand, in a bright environment such as outdoors, visible display can be obtained by using reflective display, in which light that has entered from the surroundings to the liquid crystal display apparatus is reflected by the back surface of the liquid crystal panel, and display is performed using the reflected light. In a dark environment such as indoors, the reflective display suffers shortage in the brightness.
There is known a reflective/transmissive liquid crystal display apparatus that is usable as both a reflective liquid crystal display apparatus and a transmissive liquid crystal display apparatus. The reflective/transmissive liquid crystal display apparatus has the advantages of the two display schemes. For example, JP-A 2002-107725 (KOKAI) discloses a reflective/transmissive liquid crystal display apparatus which arranges the surface light source on the other side of the observation side of the liquid crystal panel, and a transflective film between the liquid crystal panel and the surface light source. For example, JP-A 2004-93715 (KOKAI) discloses a reflective/transmissive liquid crystal display apparatus which arranges the surface light source on the other side of the observation side of the liquid crystal panel, and divides each of the plurality of pixels of the liquid crystal display device into two regions. One of the regions is used for reflective display by inserting a reflective film between the liquid crystal panel and the surface light source, whereas the other region is used for transmissive display.
For example, both the reflective/transmissive liquid crystal display apparatuses disclosed in JP-A 2002-107725 (KOKAI) and JP-A 2004-93715 (KOKAI) aim at uniting the performance of a reflective liquid crystal display apparatus and that of a transmissive liquid crystal display apparatus. However, although capable of functioning as both a reflective liquid crystal display apparatus and a transmissive liquid crystal display apparatus, they obtain only darker display and poorer visibility as a reflective liquid crystal display apparatus or a transmissive liquid crystal display apparatus as compared to an apparatus dedicated to reflective display or transmissive display.